Positive crankcase ventilation systems (PCV systems) provide a mechanism for transferring vapors from the engine crankcase, or another engine compartment containing oil, to the induction system of an engine. Many PCV systems provide some restriction to prevent engine oil from being drawn into the induction system and burned in the combustion process. As part of a PCV system, air/oil separation plays an important role in reducing the amount of engine oil that is carried into the induction system and later burned by the engine. Some air/oil separation systems include one or more chambers and baffles designed to cause oil particles entrained in the crankcase gasses to fall out of the gasses before those gasses are allowed to flow into the intake tract to be subsequently burned by the engine.
At least some PCV systems achieve air/oil separation by using a baffle plate with a series of holes. The baffle plates used in the prior art provide an effective means of separating air and oil. However, due to the relatively unrestricted path through certain baffle plates, oil that impacts the baffle plate may be able to become re-entrained in the mixture. As a result, oil is carried into the induction system and burned in the combustion process, resulting in oil consumption.